Procedures for Evaluating the Physiological Quality of Pelleted Lettuce Seeds

Seed pelleting improves handling, facilitates sowing, and allows the addition of beneficial substances. However, its evaluation requires specific methods due to the coating, which can affect water absorption, gas exchange, and seedling emergence. In this context, the present study aimed to establish an appropriate methodology for assessing the germination of pelleted lettuce seeds. The physiological quality of lettuce seeds, with and without the pellet, was evaluated using sand, vermiculite, and Germitest paper as substrates. In the sand and vermiculite substrates, three sowing methods were tested: (1) on the substrate, (2) under the substrate, and (3) in furrows. In the Germitest paper substrate, seeds with and without the pellet were sown in two ways: (1) between paper and (2) on paper. Germination was evaluated at 4, 7, 10, 13, 16, and 19 days after sowing. The experiments were conducted in a completely randomized design with a factorial arrangement. The results were subjected to analysis of variance (ANOVA). For the qualitative factor, the Scott-Knott test (p ≤ 0.05) was used, and for the quantitative factor, regression analysis was applied. The sowing method and seed status influence germination. For pelleted lettuce seeds, sowing under the substrate in sand or vermiculite is recommended for better hydration. In the Germitest paper substrate, removing the pellet and sowing between or on top of the paper promotes uniform germination.